Conventionally, an original cover closer used for office equipment such as (multifunction) printer comprises an attaching member comprising an attaching plate attached to the main body side and both side plates erected from both sides of the attaching plate; a supporting member comprising a back plate and both side plates hanging down from both sides of the back plate, wherein the side plates are rotatably attached to the both side plates of the attaching plate via a hinge shaft; a lift member comprising a back plate and both side plates hanging down from both sides of the back plate, wherein the lift member is rotatably attached onto the free end side of the both side plates of the supporting member via a lift shaft; a pressure receiving member attached between the both side plates of the attaching member; a cam slider slidably provided inside the supporting member with its cam portion abutting against the pressure receiving member; a spring bearing member slidably provided on the free end side inside the supporting member; an actuating member abutting against the spring bearing member and attached between the both side plates of the lift member; an elastic means resiliently provided between the cam slider and the spring bearing member, so as to rotatably urge the lift member in a direction in which it overlaps the supporting member and to rotatably urge the supporting member in a closing direction of the original cover; a brake means consisting of a single friction protruding ridge portion provided between a central portion of an inner wall portion of the supporting member and the spring bearing member; such an original cover closer is known as shown in Laid-Open JP Patent Application No. 2000-180993.
However, in the original cover closer described in Laid-Open JP Patent Application No. 2000-180993, since a friction protruding ridge portion constituting the brake means is narrow, this is a single friction protruding ridge portion and it is provided on the central portion of an inner wall portion of a supporting member, there is a need to make the friction protruding ridge portion higher in order to assure a necessary friction torque. In this case, it is necessary to assure an adequate clearance, thus a so-called backlash occurs in an area in which a brake means does not function. It is therefore problematic that this backlash prevents a smooth operation of the original cover closer.
Moreover, in a conventional original cover closer, a friction generating means is provided, wherein friction plates or spring washers are provided one overlapping the other between a hinge shaft and both side plates of a supporting member, in order to obtain a friction torque, thus the number of parts is increased, which is obstacle for a reduction of costs.
Still further, to date, there is no original cover closer using conventional elastic means which ensures to control a rotation movement of a supporting member and to enhance operability of an original cover closer.